using System.Collections;

namespace Test
{
    // 接口
    interface ICustom
    {
        void Fun();
    }

    class TestClass
    {
        static public void Test()
        {
            // ACustom a = new ACustom();
            // a.Fun();
            int[] arr = new int[] {1, 2, 3, 4};

        }
    }

    class ACustom: ICustom
    {
        public void Fun()
        {
            Console.WriteLine("XXXXXXXXXXXXXXXXXX");
        }
    }
}